The clinical physics core will provide all dosimetry, treatment planning, specialized patient treatment support and quality assurance for the research projects. It will support Project 2 through beam measurement and data acquisition through the use of water phantoms, film dosimetry, anthropomorphic phantoms and diode dosimetry. Support for projects 3 and 4 will include diode and TLD dosimetry in patients, and design and fabrication of patient set-up and treatment aid devices. It will support Project 1 by testing the software developed there for use in our treatment planning system and establishing the methodology for its effective use. Diagnostic imaging from CT, MR, PET and Spect scanning will be integrated into accurate target volume and normal tissue descriptions to aid in the work of Projects 1, 2, 3, 4. The mechanics and entry of information associated with image correlation will also be performed in this core to aid in the efforts of all four projects. As the research plans in each project progress and dosimetry techniques or treatment planning tools are developed, the personnel in this core will test and routinely use them. Quality assurance programs for all four projects will be carried out by the members of this core.